Pupillary membrane

remnants of the central portion of the anterior layer of the iris stroma (the iridopupillary lamina) that occludes the pupil in fetal life, and normally atrophies about the seventh month of gestation. Persistent strands usually stretch across the pupil from one iris collarette to the other, without touching the pupillary margin. Failure to regress is a rare cause of congenital blindness.

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